Based on the mechanism of action of gamma-aminobutyric acid transaminase, numerous specific irreversible inactivators have been designed and some synthesized. For those compounds which exhibit irreversible inactivation, the mechanism of the inactivation will be studied and the active site residues which are labeled will be determined. The mechanism of inhibition of some known GABA transaminase inhibitors also will be investigated. Compounds which are potent inactivators of GABA transaminase will be tested for anticonvulsant activity.